Electrical tuning device.



.I R. H. MARRIOTT. ELECTRICAL TUNING DEVICE. APPLICATION FILED NOV.13, I968 Patnted Dec; 13, 1910.

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R. H. MARRIOTT.

ELECTRICAL TUNING DEVICE.

APPLICATION FILED NOV. 1a, 1908.

Patented Dec. 1 3, 19 10. I V

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R. H. MARRIOTT ELECTRICAL TUNING DEVIGE.

APPLICATION FILED NOV. 13, 1908' Patented Dec. 13, 1910.

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Patented B90513, 1910.

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R. H. MARRIOTT, g ELECTRICAL TUNING DEVICE.

' 4 APPLICATION FILED NOV,13,19Q8-. 978,604. Patented Dec. 13,1910.

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ELECTRICAL TUNING DEVICE. APPLIOATION TILED NOV. 13, 1908.

Patented Deb.13,1910.

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ELECTRICAL TUNING DEVICE,

APPLICATION FILED N0V.13,1'908.

' Patented Dec. 13, 1910.

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R. H. MARRIOTT.

ELECTRICAL TUNING DEVICE.

APPLIOATIONPILED NOV. 13, 1908.

978,604. Patented Dec. 13, 1910.

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UNITE sirrias A ENT OFFICE.

ROBERT H. MARRIOTT, OF BROOKLYN, NEW YORK, ASSIGNOR T UNITED WIRELESS TELEGRAPHOOMPANY, A CORPORATION OF MAINE.

ELECTRICAL TUNING DEVICE.

T 0 all "whom-it may concern.-

i p Specification of Letters .Patent.

One of the objects of my invention is to.

provide one or more variable inductances,

each of which is adapted to be connected in. its respective aerial or local circuit, and

which ind ictan'c es are also adapted to be inductively or conductively connected with.

iclation to each other, together with switching means for changing from the inductive to the conductive connection at will.

Another object of my invention is to'connect an aerial and local nductance in their respective circu ts, and to provide switching means for varying the kind of conductive connection between the aerial and local in ductai ce at will.

A more particular object of my invention, s to provide means so that said aerial 111- ductance may be; thrown in-series withsaid local inductance, both inductances being 111- cluded in one local circuit, with the coils of the two inductances connected so that the self-induction of the coils is greater than that of either coil acting alone or with the coils so connected that the self-induction of the coils is less than that of either coil.

Another object of my invention is to provide means whereby the aerial inductance may be thrown in series with the local circuit. and said aerial, with the coils of the aerial and local. inductance in agreement or opposition.

Another object of my invention is to pro vide a variable inductance for a high frequency transmission of electrical energy comprising a plurality of coils with means for including one or more of said coils in a from said circuit so as to avoid connecting the dead ends of the coils with the circuit.

circuit and disconnecting the remaining coils \Vitl'rthe above and other objects in view, 1 my invention consists in the parts, improve- Patented Dec. 1'3, 1910.

Application filed November 13, 1908. Serial No. 462,496.

ments and combinations more fully set fortli A hereinafter;

Turning now to the drawings which are attached to the specification and form a part thereof, Figure 1 is a diagrammatic view of the entire system. tion illustrating one torin of thevariable inductance used in the tuning apparatus. Fig.3 is a horizontal section of the variable inductance, with the sliding frame partly Fi 2 is a vertical. secpulled out. Fig. i is-a transverse vertical section of the apparatus shown in Fig. 2-. Fig. 5 is a front view of the variable induc-' tance illustrated in Fig. 2. Fig. 6 is a section through one of the regulating switches illustrating the connection of the induction coils with the conductors controlled by the switch. Fig. 7 is a developed view of the surface of the regulating switch shown in Fig. 6. Fig18is a sectional detail through the regulating switch shown in Fig. 6. Fig.

'9 is a longitudinal. sectional detail of the switch for throwing the inductances in various relations with each other. Fig. 10 is a transverse sectional detail of the switch illustrated in Fig. 9. Fig. 11 is an end view of the switch shown in Fig. 9. Fig. 12 is a diagrammatic view illustrating the arrangement of switch contacts of the switch shown in Fig. 8. Fig. 13 is a vertical section of the complete tuning apparatus. Figs. 14:, 15, 16, 17 and 18 are diagrammatic views illustrating some of the various connections that may be made by means of the invention.

In the particular embodiment of the inv vention' illustrated upon the drawings, the

high frequency system of jtransinis'sionof energy includes an aerial 1, which is preferably in the form of a loop. The loop comprises antennae wires 1 2, 3, 4, which wires are connected together at 5 so as to be conneetible by means of the switch 6 to the tuning circuit. The other end of the loop may be connected through switches 7, 8 with a variable inductance 9. Two switches 10 and 11 which will'be more fully described varied. In the particular embodiment of the invention illustrated upon the. drawings,

its appropriate zone or strip.

a plurality of inductance coils ll. 15,'each electrically disconnected from the others. The coils are preferably divided 1nto sets.

-As illnstratedtwo sets of coils are carried 1 by the fixed frame one 15 consisting 0t two turns of wire each, and the other 1-1- of i ten turns. matic, it being understood that the coils are These illustrations are diagramso wound that the inductance Off each of the 5 coils o't one set is substantially a multiple of the inductance of each of the coils ot the 1 other set. This permits a variation of the inductance in small and uniform amounts.

A plurality ot regulating switches is provided. one for each se of coils in order to connect one or more of the coils in circuit.- The form of the switches may be widely raried; As illustrated, they comprise a carrier which may take the form of a shaft 16. The shaft is provided with a= finger wheel 17. A plurality of sets of conductors 18, each insulated from the other by an insula-- tor 19 is carried by said shaft. These conductors preferably form conducting .segments which extend part wayhround the insulating material. each segment lying in The heads ot'the conductors 18 are prete'ably staggered with relation to each other. As illustrated. they lie on a helical curve about the shaft 16.'which is clearly shown in Figs. 1 and T. The feet of the conductors are preterably arranged in a row which extends parallel with the shattlti. It, will be observed that the conductors dittcr inlength from each other by substantially equal amounts. A plurality of conducting pins '20 is likewise carried by the carrier. These pins project through the insulating covering 19.

They are electrically connected together. preferably by screwing one end of each pin into the metallic conducting shaft 16. as illustrated at 91. Each pin is preferably within the zone or strip which contains the conductor 18, and is arranged opposite the head of the conductor. is also arranged alongside of the head of the conductor adjacent. to the zone or strip containing the pin. ment of conductors and pins forms a simple. ettective and compact switch.

Means are provided whereby one terminal of each coil 15 may be connected to a respective pin and theother terminal of the coil to'its respectiresegmental conductor. To accomplish this result, a plurality of metallic brushes 22 are arranged in pairs and each brush connected with the respective terminal of the coil 15. A.n end brush it is connectible to one part of the circuit, and the shaft 16 through bracket 27 Eachpin and wire 26 to the other side of the circuit. The brushes, pins and anducting segments are so arranged that. as the regulating switch is turned by the finger wheel 17 one or more of the coils 15 is connected in circuit. the remaining coils of the set being disconnected from the circuit. The circuit; wires 9,- 26 lead to the end brush Q4. and bracket QTrespectively. the bracket being electrically connected with the shaft 16. As shown in Fig. 1. the circuit is completed through end brush 2 t coinluctiug segment 18. brush coil 15 to the adjacent segment 13 which in turn electricallv connects the coil with thrush leading to the next coil and so on until a conducting pin is reached.

By means ot the pin the circuit is completed through the shaft; 16 and wire 26. The coils at the tar side 01 the pin,'2'. 0. beyond the point where the circuit is completed are disconnected from the circuit and consequently do not. add perjudicial inductance or capacity thereto. The brushes 2)- are carried by an insulating strip 28 to which they are secured by screws 29. The bracket 27 is likewise secured to the strip 28 by screws 30. 18 are secured to the insulator 19 by screws 31 or other suitable means.

I preferably employ a plurality of regulating switches for throwing the inductance coils into circuitione for each set of coils. The unit coils 15 are thrown in by one regulating switch and the multiple coils 14: by another. As shownin Fig. 1, the regulating switch for the coils He is provided with a shaft 32jand finger wheel 33. insulating material 3 1, conducting segments 35. pins 36, terminal brush 3?, and brushes 2:58 for the ends of the coils 1-1. The various parts are connected and arranged as heretofore described in connection with the unit coil .as to ellectively close and protect the coils and regulating switches from dust and damp. A guide rod is used to guide the sliding :trame. The rod is preferably remorably secured at one end to the casing. A

j washer L1 pinned to the rod it) by a pin iii The described arrangej and a nut 1H screwed on the end to of the rod, which presses against a washer +13. removably secure the rod in place. The other end of the rod unsupported and tree. The sliding frame is guided in its movements by the rod which passes through a hole -16 in the plate 47 secured to a part of the frame by screws &8. A hole d0 in the cover 30 centers the frame when it is in its innermost position. A handle :30 enables the operator to slide the frame. The cover 39 is also guided A in 5t which when The conducting segments 1.9 ing a multiple of that of the other set.

The coils are preferably wound around theoutside the sliding frame, which as well as the fixed frame, is preferably cylindrical. in form and circular in cross section. Elec= trical connections'57 pass from the ends of the inductance coils through the sliding frame to be connected at the inside thereof to suitable brushes 58. These brushes are arranged in pairs, one pair for eachcoil.

. An end brush 59 is'connected in circuitas indicated in Fig. 1. The brushes are iiisulated from each other and attached by means of screws '60 to an insulator 61. One or more regulating switches, onefor each set of coils are arranged within the sliding frame and carried thereby. As illustrated the switch for the multiple set of inductances includes a. shaft '62 provided with a finger wheel 63. The shaft is covered with insulating material 64 and carries conducting segments 65 and pins 60 with which the brushes 58 are adapted to contact. The parts are arranged to. throw in successive coils and keep the remaining coils disconnected from the circuit in the same manner as heretofore described in connection witl theswitch for the coils 15. An-

other switch is provided for the unit coils carried by the sliding frame; It is 7 pro- ,vided with a shaft 67, finger wheel 68, insulator 69, conducting segments and pins '71. In each switch the conducting segments are insulated from each other and the pins are electrically connected, preferably to the 5 5' unison.

shaft. 'A terminal brush 72 connects the inductance to the circuit at one point, the other connection being made through the shaft and bracket 73.

Suitablemeans are provided for connect- 5o ing the variable inductances either inductively or conductively with respect to each other,- and. means are also provided to connect the windings of the inductances in 0ppositionjor in agreement, that is to say in Some of the ways in which, in accordance with the invention, the windings are adapted to be connected are illustrated in 60 connections.

shaft 74 with insulating material 75' carried by arms 76 secured-t0 a base7 7 by screws 78. The switch is contained'in a box 79. 'The insulating material ofthe switch carries a series of conducting platesSO, 81,82, 83, 84,

8.5, 86, 8'7, 88, 89, 90, 91, 92. Theseplates are arranged in accordance with the invention to connect the inductance coils in the ways necessary for practical working.

A plurality of brushes 93, whose ends 94 are adapted to contact with the plates 8092 are respectively connected to binding posts 95, 96, 97, 98, 99,100, 101. Branch wires 102, 103, 104 are used so asto connect each of the binding posts 95, 96, 0S with two brushes. A scale 105 and'pointer-AOG indi- 'cate each of the five positions at which the switch is placed, lettered a, b, 0, (L16, which correspond to five of the connections made by theoperator. .In order that the switching means may connect the tuning inductances, the local and aerial condensers, the

aerial andthe. receiver in the various ways indicatedin Figs. 14 to 18, the bindingposts s 95, 90, 97, 98, 09, 100, 101 of the switch are electrically connected by connecting wires to various parts of the apparatus. These connections are made manually when the appa- 'ratus'is setup. By then turning the shaft '74 of the switch, the various, combinations required are effected. The wired connections of the switch.

Binding post is connected by a wire with binding post 950(Fig. 13) at oneside of the aerial condenser; "The other side of the condenser connects to ground via terminal 111. Binding post is connected by a wire with binding post 060 (Fig. 4) which connects the brush 24 at one end of the regulating switch that includes shaft 10., Binding post 97. is connected bya wire with one side of thetelephone receiver. Binding post 98 is connected by a wire with binding post 980 (Fig. 4) at one end of the regulating switch that includes shaft 62. Binding post 99 is connected by a wire with post 090 'will first be described and then the operation 13) at one side of the local condenser circuit. Binding post 100 is connected by a wire with post 1000 (Fig. 4) which leads to the shaft 32 and binding post- 101 is connected by asuitable wire topost 1010 which connects with brush 7 2 (Fig. 4). The terininail 150 of the local condenser circuit and the remaining terminal 151 of the receiver circuit are connected together by a wire.

Connectors 140, 141 connect theunit induc- .tances of the aerial circuit with thegnultiple inductances of the aerial circuit and connectors 142, 143 are used to make the same connection for the lOCflhlDdUCtflIiCGS.

. Fig. 14 illustrates diagrammatically the capacity 110, (the variability of thecapacity of the condenserbeing indicated by the arrow) and then to ground through the connection 111 and switch 111. The local circuit which contains the condenser 112wand telephone receiver 113 also contains the variable tuning inductance 11, 15, The two sets of inductances are in series in the local circuit. This system of connection corresponds to position (.1 of switch 71 with blocks, 80. 81, S2 in contact with their respective brushes.

The diagram of Fig. 15 shows the inductances arranged in conductive relation with their coils in agreement or unison that is so that the inductive effects of the separate coils assist each other, thereby increasing the self induction of the circuit. The two sets of inductances are in series in the local cireuit. This corresponds to position Z) of the switch 71 with blocks '83, 8st, 85 in contact with the brushes.

Fig. 16 illustrates the inductances in conductive relation withtheir coils in opposition, thus more or diminishing the joint self inductance of the coils. This corresponds to position 0 of the switch with blocks 86, '87, 88 in contact with their respective brushes,

Fig. 17 illustrates the inductances so arranged that one is contained in the local circuit and the other is in series with the aerial. and the local circuit. The coils of 'the'respective inductances are arranged in agreement orunison so as to add their selt This corresponds to position (Z' induction. of the switch with blocks 89 and 90 in contact with their respective brushes.

Fig. 18 illustrates the inductances so arranged that one is in the local circuit and the other is in series with the aerial and the local circuit. The coils of the respective inductances are arranged to oppose each other, so that the total self induction more or less diminished. This corresponds to position 0 of the switch 74 with the blocks 91 and 92 in contact with their respective brushes.

By the above described circuit connections and by sliding the sliding frame carrying one set of inductance coils in and out, the sell induction of the circuit may be greatly varied so as to tune the apparatus for many diil'erent wave lengths and to distinguish between signals varying in intensity alwere used as on shipboard it the ship rolls. The local variable condenser 112 may be connected in circuit in any desired manner, for example in shuntor in series with the telephone. receiver and the variable condenser in the aerial circuit may be connected at any desired point in that circuit. The in ductance 9 for the aerial loop is preferably divided so that a part of the inductance is placed'in each branch of the loop. I employ two switches 10 and 11 to secure this result. The inductance 9 is wound around the drum 160 and the switches 10 and 11 slide lengthwise of the drum. These switches are constructed as follows: A slide 130, which slides in a suitable groove is cut away so as to receive the finger. .A metallic brush 1.31 with head 132 is carried by the slide, the head contacting with the bare wire '9 of the inductance. One end of the inductance is grounded at 134. The brush 131 connected in circuit through the connector 133 and the switch 10 is connected in circuit through the connector 135. These switches afford a means for varying the inductance in each branch of the loop.

Having thus described one embodiment of the invention, it will be obvious that many changes may be made in its form without dc )arting from the principle thereof.

lVhat I claim and desire to obtain by Letters Patent, is the following:

1. In a high trtquency system of trans mission of energy, the combination of a receiving circuit, a variable inductance arranged in said circuit, a local circuit, a variable inductance in said local circuit, all of the inductance in the receiving circuit being adapted to be connected either inductively or conductively with relation to the inductance in the local circuit and switching means for changing from the inductive to the conductive connection at will.

2. Ina high f equency system of transmission of energ an aerial, a variable inductance in circuit with saidv aerial, a local circuit including a variable inductance, said inductances being adapted to be connected either inductively or conductively witl1 respect to each other, means for grounding said aerial circuit and-switching means for changing from the inductive to the conductive connection at will.

3. In a high frequency system of transmission of energy, an aerial, a variable inductance in circuit with said aerial, a local circuit including a variable inductance, a receiver in said local circuit, said inductances being adapted to be connected either in ductively or conductively with respect to each other. means for grounding said aerial.

mission, the combination of a grounded aerial, a variable aerial inductance in circuit with said aerial, a local circuit includ ing a receiver, a local variable inductance and switching means whereby said aerial inductance and local inductance may be thrown in series with each other in said local nectible from the other, another frame carry nectible from the circuit, and a regulating ing a plurality of inductance coils, each insulated from the other and each disconnectible from the other, a regulating switch for connecting one or more of said first named coils in circuit, a regulating switch for connecting one or more of said latter coils in circuit of said frames with respectto the other so as to vary the inductive relation between,

of inductance coils, each insulated rom the other, the coils being electrically disconswitch for including in circuit one or more of said coils at will. 7

7. In a high frequency system of transmission of energy, the combination of a circuit to be tuned and a tuning apparatus therefor, the latter includinga plurality of inductance coils, a regulating switch, means for connectingin circuit one or more inductance coils at will; a second lurality of inductance coils adapted to e inductively connected with the first set of inductance coils and a regulating switchfor conductively connecting the second set of inductance coils in circuit in series with said firstnamed set.

8. In a high frequency system of transmission of energy, the combination of a cirs cuit to be tuned and a tuning apparatus therefor, the latter including a plurality of inductance coils, a regulating switch adapted to connect one or more of said coils in series in a circuit, a second plurality of in ductance coils, a regulating switch adapted to connect said second plurality of coils in a circuit, frames for carrying the two pluralities of coils adapted to bring them into I inductive relation with each other, and a switch adapted to connect the two 'pluralities of coils in circuit with their'windingsin unison or in opposition, I

9. In a high frequency system of transand means for moving one switch, a conducting shaft on which said mission of energy, the combination of a Cir-,L cuit to be tuned and a tuning apparatus therefor, the latter including a plurality of" inductance coils electrically disconnected from the circuit, each coil having an inductance equal to or a multiple of a common unit, and regulating means for including one or more of said coils in a circuit, and. disconnecting the remaining coils from said circuit. v

10. In a high frequency system of transmission of energy, the combination of a circuit to be tuned andna tuning apparatus therefor, the latter including a plurality of inductance coils, areguilating switch carrying a plurality of sets of conductors, the conductors of one setbeing insulated from each other, and the conductors of another set beingconductively connected,means for connecting one terminal of each coil to the 85 respective conductor of the connected set and means for connecting the other terminal of each coil to its respective insulated conductor.

11. In a high frequency system of trans- 9o mission of energy, the combination of a circuit to be tuned and a tuning apparatus therefor, the latter including a plurality of inductance coils, a rotatable regulating switch is mounted, a plurality of conducting segments carried by said shaft and insulated therefrom, a plurality of conductors insulated from said segments, but electrically connected with said shaft, a plurality of brushes arranged to contact respectivel W with said segments and said conductors an means for electrically connecting the ends of the respective inductance coils with corresponding brusbes. Y

12., A high frequency receiving system comprising an aerial, a plurality of inductance coils, a regulating switch carrying a pluralit of sets of conductors, the conductors 0 one set being insulated from each other and the conductors of another set being conductively connected, means for connecting one terminal of each coil to the respective conductor of the connected set, meansfor connecting the other terminal of each coil to its respective insulated conductor and means for connecting one of said insulated conductors tothe aerial and'one ofsaid connected conductors to ground. I

13. In a high 12o frequency system of transmission of energy, the combination of a cir' cuit to be tuned and a tunin apparatus therefor,th'e latter including a ame carrying a lurality of inductance coils, each electrical y disconnected from thcother, a sec- -ond frame carrying a plurality of induc- Ytance coils, each electrically disconnected from the other, the frames being arranged to telescope one within the other, electrical 3,

connectors carried by each of said frames for respecti ely connecting said inductance coils in circuit. and one or more regulating switches for connecting one or more of said inductance coils with said connectors.

ii. In a high frequency system of transmission of energy, the combination of a circuit to be tuned and a tuning apparatus therefor, the latter including a plurality of inductance coils, an outer fixed frame (in which said coils are mounted, an inner sliding frame carrying a plurality of inductance coils and a regulating switch carried by said sliding frame for connecting one or more of the coils on the sliding frame in circuit.

15. In a high frequency system of trans mission of energy, the combination of a circuit to be tuned and a tuning apparatus therefor, the latter including an outer frame. carrying a plurality of inductance coils, an inner frame carrying a plurality of inductance coils arranged in sets, the inductance of each of the coils of one set being substantially a multiple of the inductance of one of the coils of another-set and a regulating switch carried by said inner f zone for con-- necting one or more of the coils of each set of coils carried by the inner frame in circuit.

16, In a high frequency system of trans mission of energy, the combination of a circuit to be tuned and a tuning apparatus therefor, the latter including an outer frame carrying a plurality of inductance coils, an inner frame carrying a plurality of inductance coils arranged in sets, the inductance of each of the coils of one set being sub.

stantially a multiple of the iinjluctance'of one of the coils of the other set, and a plurality of regulating switches, one for each set of coils for connecting one or more of the coils of the set in circuit.

17. In a high frequency system of transmission of energy, the combination of a circuit to be tuned and a tuning apparatus therefor, the latter including an outer frame carrying a plurality of inductance coils, an inner frame carrying a plurality of inductance coils arranged in sets. the inductance of one of the. coils of one set bcing substantially a multiple of the inductance of one of the coils of the other set, and a plurality of rotary regulating switches. one for each set of (oils for connecting one or more of the coils of each set in circuit.

18. In a high frequency system of transmission of energy, the combination of a circuit to .be tuned and a tuning apparatus therefor. the latter including an outer cylindrical fixed frame, a plurality of sets of im'luctancecoils wound around the outside of said frame, the inductance of each coil of pne set being substantially a multiple of the inductance of a coil of the other set, a plurality of brushes with which the ends of said coils are respectiycly connected, a plurality of regulating switches for said coils, said regulating switcl es including a shaft, a plurality of conductors adapted to contact with said brushes. said conductors being arranged with their leading ends in a spiral curve about said shaft. a plurality of conduclii'i'g pins insulated frma said conductors, each pin arranged in advance of a correspiaiding conductor, means for eltattrically connecting said pins and means for connecting said pins in circuit.

19. In a high frequency system of transmission of energy, the combination of a circuit to be tuned and. a tuning apparatus therefor, the latter including a casing, a fixed frame within the casing, a plurality of inductance coils wound around said frame, a sliding frame arranged to slide into and out of said casing, a plurality of inductance coils carried by said sliding frame and a cover attached to said sliding frame and adapted to close said casing when said sliding frame is within said casing.

20. In a high frequency system of transmission of energy, the combination of: a ci rcuit to be tuned and a= tuning apparatus therefor, the latterincluding a casing, a fixed frame, a plurality of inductance coils carried by said fixed frame. a guide rod, a sliding frame. a plurality of inductance coils carried by said sliding frame, said sliding frame being guided in its movements by said rod, a cover attached to said sliding frame and guiding means for said coyer.

21. In a high frequency U tem of transmission of ei'iergy, the cmnbination of a circuit to be tuned and a tuning apparatus therefor, the latter including a casing,- a fixed frame, a sliding frame, a plurality of sets of inductance coils wound around said sliding frame, a guide rod rigidly secured at one end to said lixtal'frame, the other end of the guide rod being unsup mrted and means for guiding said sliding frame on said guide rod. p

1 ,111 a high frequency system of transmission of energy, the combination of; a circuit to be tuned. and a tuning apparatus therefor, the latter including a casing, a

means for removably securing one end of said guide rod to the frame of the appara tus, the other end of the guide rod being unsupported, a sliding frame, a plurality of inductance coils wound around said sliding frame, said latter frame being adapted to be guided on said guide rod, a cover secured to said sliding frame, a plurality of regulating switches carried by said sliding frame, said regulating switches being adapted to include one or more of said inductance coils in'circuit.

23. In a high frequency system of trans- .the inductance coils and the respective brushes, said connections passing through said frame. f a t 24. In a high frequencysystein of transmission of energy, the combination of a cir- -cuit to be tuned and a tuning apparatus therefor, the latter including a fixed frame, a plurality of inductance coilswound around said frame, a sliding frame arranged to slide within said fixed frame, a plurality of ind'uctance coils wound around the outside of said sliding frame, one or more shafts extending longitudinally of said sliding frame, a plurality of conductors carried by said shafts, said conductors being insulated from each other and from said shafts, the heads of said conductors being arranged s )irally I around their respective shafts, a plura ity of conducting pins each arranged opposite the lieadvof one of the conductors, means for electrically connecting said pins, a plurality of brushes adapted to contact with said con,- ductors and said pins and electrical connecting meanszconnecting the ends of the respective coils to respective brushes.

25. In a high frequency system of transmission of energy, the combination of a cir;

cuit to be tuned and a tuning apparatus therefor, the latter including a plurality of inductance coils normally disconnected from each other, a plurality of brushes including an end brush, the ends of the coils being connected to respective brushes, a carrier, a plu rality of conductorsca'rried by said carrier, each insulated from the other, the heads of the conductors being staggered with relation to each other, a plurality of conducting pins, each pin arranged within the zone of the corresponding conductor in front of said conductor and alongside of the head of the adjacent conductor, means for electrically connecting said pins, means for connecting the circuit to one of said pinsv and means for connecting another portion ofthe circuitto the end brush. f

26. In a high frequency system of transmission of energy, the combination of a cirmat to be tuned and: a tuning apparatus --therefor, the latter including a plurality of inductance coils, a plurality of pairs of brushes, a plurality of inductance coils, each coil having its ends connected respectively to the brushes of a pair, means foninsulating each pair of'brushes from the adjacent pair, a plurality of conductors each insulated from the other and mounted upon a common carrier and adaptedto successively connect adjacent brushes, a plurality of conducting pinsinsulated from each other and mounted upon said carrier, each of said pins being adapted to successively contact with the terminal brush of a coil, when the other brush attached to said coil is electrically connected through one of said conductors with the adacent coil, means for electrically connecting said pins and means for connecting said pins in circuit. I I v t 27. In a high frequency system oftransmission of energy, the combination of a receiving circuit, avariable inductance arranged in said circuit, a local circuit, a 'variable inductance in sa dlocal circuit, said inductances being adapted to beconnected either inductively or conductively with rela-- tion to each other, switching. means for changing from the inductive to the conductive connection atwill and means for moving one of said inductances with r'elation to the other so as. to vary the inductive rela-' tion between them;

28. In" a highfrequency system oftrans mission of energy, the combination of a cirwit to be tuned and a tuning apparatus therefor, the latter including a plurality of inductance coils, a regulating switch, means "for connecting in circuit one or more inductance coils at will, a secondplurality of'inductance coils adapted tobe inductively connected with the first set of inductance coils, a regulating switch for conductively connecting the second set of inductance coils in circuit in series with said first named set and means for moving one of said inductances with relation to the other so as to ary the inductive relation between them.

29. A tuning apparatus for, high fre-.

quency system of transmission of. energy comprising casing containing a balanced local and aerial condenser of variable caacitv aninductance a air of slidin a) 7 b switches adapted to, connect vone or more turns of said inductance in the branches ofan aerial loop,a local inductance, an aerial inductance, a plurality of regulating switches for connect ng said local and aerial inductance respectively in circuit.

30. A tuning apparatusfor high frequency system of transmission of energy comprising a casing containing a balanced local and aerial condenser of variable capa'city,ran inductance, a pair of sliding, switches adapted to connect one or more turns of said iii'ductance'in the branches of an aerial loop, a local inductance comprising aplurality of coils electrically disconnected, an aerial inductance oomprising a plurality of coils electrically disconnected, a plurality of regulating switches for aionnecting one or more of said local and aerial inductances in circuit i-onnecting' the rmniiining coils .in

eluding the eoiuhiniition of ii plunlity of I llltltlt'ltlllt't coils electrically disconnectible itroni each other. and switching 1ne:i'ns for connecting one or more of said coils to the circuit to hotuned without connecting the rein-mining coils to the circuit thereh i' m'oiding the connection of deud ends to the cir- 3 cuit.

3;. A tuning apparatus for a high freuuencv system of t1'2l1l5111l f l011 of energy comprising the ombination of :1 plurality of llltllHlttllCL coils. one of which may he electrically discoi'ineetetl from the remaining coils and switching niezins for connecting said coil to the circuit and disconnecting the remaining coils from said circuit whereby the connection of the deud ends 01'? the renniining coils with the circuit: is avoided.

I33. tunin apparatus for a high frequcncy t l'tlil of transmission o't energy (JOlllPllHillg the coni iiii'izition of one or more l inductance coils adapted to be connected in l series with each other and electrically dislconncctihle front :1 circuit and switching l 111021118 for conncctii'i g one or more of sand coils in series with each other and to said circuit and disconnecting the remaining coils ,il'Olll said circuit. thereby avoiding the connection of dead ends to the circuit.

M. A tuning apparatus for ii high :lre- 'quencr system oit transmission of energy (ZOIllPllSlllg the combination of one or more l ind uct'nnce coils electrically discon'ncctililc from n circuit and :i inorzihle switch for con necting' one or more of snid coils to said ciri cuit tllltl disconnecting the renniining coils from said circuit, thercln avoiding the con nection of dead ends to the circuit.

In testimony whereof, I have signed iny two subscribing witnesses.

ROBERT H. MARRIOTT.

lVitncsses V. C. Mnnonsox, W. 1*. BISMNG.

nznno to this specification, in the presence of- 

